Tube and sheet connection



Patented Feb. 5, 1929.

'rnonAs wnmrnl LOWE, or wminrne, M NITOBA, CANADA.

' rum AND snrmr connncrron.

Application flleddiovember I, 1921. Serial No. 511,974.

My invention relates to tube and sheet connections particularly usefulfor the attachment of water circulation tubes to the tube sheets oflocomotive fire boxes. The invention is of especial advantage in fireboxes with very shallow throat sheets (particularly those of the Wootentype), afl'or ing a novel attachment of the arch suptporting water tubesin such a fire box to the ue sheet itself above the throat sheet, highenough to give the tubes a practical firing clearance above the grate.

How these and still other advantages can be obtained through myinvention will. ap-

pear from my description hereinafter of the best embodiment known to me.p

In the drawings, Figure 1 shows a vertical longitudinal section throu ha boiler fire box of the locomotive type wit an arch supporting tubesecured to the flue sheet above't-he throat sheet in accordance with myinvention.

Figure 2 shows an enlarged section through the tube and its joint withthe flue s eet.

Figure 3 is a fragmentary view, similar to Figure 1, but on a largerscale, showing the attachment of a tube to the tube sheet in accordancewith my invention.

In Figure 1 is shown a locomotive type boiler 4 with quite shallowthroat sheet 5.

In the fire box 6 is an arch of fire brick- 7 supported on fore and aftwater circulation tubes 8 that are connected to the rear wall 9 of thefire box above the fire door 10, in the usual way. The forward ends ofthe tubes 8,

however, are not connected to the flue sheet below the shallow throatsheet 5, as is usual,

but are bent upward slightly at 11 and attached to the flue sheet12,above the throat flange 16 is seated and secured in a bevel edgedrecess or depression 17 in the rear side of the sheet 12, around a hole18 therein that sheet, but below the fire tubes 13. As shown, thisconnection is not made by expanding the coincides, in both size and'position, with-the inside of the tube 8. The flange 16 may be secured tothe sheet 12 (which is in effect a tube sheet in reference to the tubes8) by welding. As shown, the front face of the flange 16 may beautogenously welded to'the bottom of the recess 17 as by spot-welding;and its bevel-edged periphery ma be fusionwelded to the peripheral'wallof t e recess by means of interposed added metal 20. As 6 illustrated,this added metal 20 is also fused and welded about the tube 8 over theflan e 16, at 21, so as to reinforce and stiffen t e tube and itsconnection to the sheet 12 at this point, and to afford protect-ionagainst burning of the joint in service.

,Welding. of the tubes 8 to the rear side of the sheet 12 obviatesallnecessity for the presence of plugged openings opposite the forward endsof the tubes,such as would 7 be necessary if the tubes had tobe expandedin the sheet 12 when being installed or replaced,--and is thus importantin enabling the tubes to be attached, as shown above the throat sheet 5,where openings could not well be provided. Such a relatively highlocation of the forward ends of the tubes 8 is of importance inaffording a practical firing cleartype.

In Fig. 3, the forward ends of the tubes 28 are shown as slopingdownward unbent and attached to the tube sheet 5 in the manner 5illustrated in Figure 2. Though not required for installation orreplacement of the tubes 28, openings with screw threaded clean-outplugs 29 are provided in the outside sheet 30 opposite the tube ends. 0

I claim:

1. The combination with a tube sheet, of a tube with external flangeseated andwelded in a lateral recess in the face of said sheet whencesaid tube extends.

2. The combination with a tube sheet, of a tube with external flangeseated and eripherally welded in a lateral recess in t e face of saidsheet whence said tube extends.

3. The combination with a tube sheet, of

a tube with external flange seated and weldrecess in the face of saidsheet whence said ed in a lateral recess in the face of said sheet tubeextends, said flange being secured in the whence said tube extends, witha protecting sheet and reinforced and protected at its rear 1reinforcement welded about said tube over by a fusion weld of addedmetal. said flange at the same side of the sheet. In testimony whereof Ihave hereunto 4. The combination with a tube sheet, of a signed my nametube with external flange seated in a lateral THOMAS WM. LOWE.

